Ignore assertion comparison for kube_network_node_prefix when using calico (#5632)

* Fix incorrect assertion comparison for kube_network_node_prefix

* Ignore assertion comparison for kube_network_node_prefix when using calico

* Adding more var docs description for kube_network_node_prefix

* Fixing trailing whitespaces

docs/vars.md

@@ -57,7 +57,10 @@ following default cluster parameters:
 * *kube_pods_subnet* - Subnet for Pod IPs (default is 10.233.64.0/18). Must not
   overlap with kube_service_addresses.
 * *kube_network_node_prefix* - Subnet allocated per-node for pod IPs. Remaining
-  bits in kube_pods_subnet dictates how many kube-nodes can be in cluster.
+  bits in kube_pods_subnet dictates how many kube-nodes can be in cluster. Setting this > 25 will
+  raise an assertion in playbooks if the `kubelet_max_pods` var also isn't adjusted accordingly
+  (assertion not applicable to calico which doesn't use this as a hard limit, see
+  [Calico IP block sizes](https://docs.projectcalico.org/reference/resources/ippool#block-sizes).
 * *skydns_server* - Cluster IP for DNS (default is 10.233.0.3)
 * *skydns_server_secondary* - Secondary Cluster IP for CoreDNS used with coredns_dual deployment (default is 10.233.0.4)
 * *enable_coredns_k8s_external* - If enabled, it configures the [k8s_external plugin](https://coredns.io/plugins/k8s_external/)

roles/kubernetes/preinstall/tasks/0020-verify-settings.yml

@@ -85,6 +85,7 @@
   when:
     - inventory_hostname in groups['k8s-cluster']
     - kube_network_node_prefix is defined
+    - kube_network_plugin != 'calico'
 
 - name: Stop if ip var does not match local ips
   assert: